Sharp SF-7300 Service Manual page 27

I
SF-7300
SF-7350
~ HIGH VOLTAGE UNITS
1.
High voltage units
Drumcurrent
output
Limits
Tokranmhtwsen
High VOMgO UnR
both@es
Main corona 4.8KVDC
—27 ~ ~, m-.
Transfer c orona 4.5KVDC —12 1.+
+, mm.
2. Corona wire replacement
Refer to the figurebakw for replacementof the coronawire.
(Coronawire mustbe repbced at every 30000 copies.)
(1) Main corona unit (MC UN)
—
Ir
k
-+11. 5+0. h
(2) Transfer corona unit
~ten
turns.
' 15io. 5m'
(Pr=autlons when replacing the corona wires)
(1) Tti coronatire must not be twfstedorkhked.
(2) Cknths corona wirs after r~acement~ isopropand &
cohoionly.
(3) W~edry after cbening.
(4) Use the 70 microncorona wire (DWlR446=S~.
Stretchtie coronawire,
Tension sprfng
then M it at the base of
V "K;R"'ht"'w
(Transfer arena removal)
(1) Open the clam shall.
(2) RerrrovetheSorewthat hoti thetransfer coronaunit.
(3) Pull out the transfer corona unit from the rear frame side,
take care notto damage the removertape.
Removertapa
/
TC UN
/
Rear frame side
(Pr=autlona when installing the transfer corona unit)
Insert the protrueiti on tie transfercorona unh into the g- hob
of the paper gu.de E on the frontframe side.
Frontframe dde
3. High
voltageunitoutputadjustments
(DCD).
(3) Digitalmukhster(ormiwo ammeter).
NOTE: The meter must have a msssudng range of O to
low witha toleranceof *lYo
(2)
The high voltage unit must be adjust~ for any
one of the following reasons:
(1) After r eplacement ofthemain ortransfer
highvoftageunfi.
(2) After replacementof the main or transfercoronaunit.
(3)
Corona output adjustment procedures:
a.
Main corona current adjustment
(1) Remove the devdoper unit, drum unit, main corona unfi, and
transfercoronaunitfromthe copier.
(2) Rmovethe dischargelamP.
J I
3 to 5mm
Remove the cbaning bbde fromthe drum ho~er.
(3) Installthe MD sheet and secure *on the drum usingtape.
7-1